Part 5
Vehicle Dynamic Suspension (Part 5)Air Springs
Rear Height Sensor (Part 2):
Air Springs (Part 1):
Air Springs (Part 2):
The air springs on the front and rear suspension are similar in construction. The air springs are manufactured from a flexible rubber and each air spring forms an air tight cavity which provides the required spring rate for each corner of the vehicle.
As the air spring is compressed, the rubber material compresses and rolls down the side of the vertical housing (piston) below the spring. An air connection port is located on the top of each spring and allows air to be added or removed from each spring. The port is connected via a Voss connector and a plastic tube to the valve block on the reservoir.
Replacement of an individual air spring does not require a full depressurization of the air suspension system. Only the corner concerned need be depressurized. This is achieved using a routine in T4.
When servicing of an air spring or a full system depressurization is required, the weight of the vehicle must be supported before the system is depressurized. On reassembly, the air spring must be fully pressurized before the weight of the vehicle is applied to it.
AIR HARNESS
AIR HARNESS (PART 1):
AIR HARNESS (PART 2):
The system is interconnected via 6 mm diameter blue, yellow and black colored nylon pipes. The yellow pipes denote the right hand side and the black pipes denote the left hand side. Blue colored pipes are used to show the pipes which connect the front and rear valve blocks to the reservoir valve.
The air harness comprises a main harness which is located along the full length of the vehicle and connects the reservoir valve block to the front and rear valve blocks and the reservoir and four separate harnesses which are used to connect each valve block to the air springs.
The pipes are attached to the subframes and vehicle body with clips. To ensure that the correct routing is maintained, the pipes have timing marks which align with various clip positions. The timing marks are in the form of a white band around the pipe, indicating the clip position. If the correct routing is not achieved, unnecessary tension at the pipe joints will occur resulting in possible early failure.
If a pipe becomes damaged, an in-line connector is available for repair purposes. The pipes are secured to the body and the chassis with a number of plastic clips.
LEAK DETECTION
Leak detection can be carried out using a Land Rover approved leak detection spray.
If the vehicle appears to be leaking, perform a leak check on all aspects of the system, i.e.; air spring hose fittings and the associated connections on the valve blocks, air springs and reservoir. Failure to correctly diagnose leakage will result in unnecessary exchange of serviceable components and recurrence of original problem.
AIR SUSPENSION CONTROL MODULE
The air suspension system fitted to Range Rover is controlled by the air suspension control module which is located adjacent to the passenger compartment fusebox, behind the instrument panel. The control module is housed in a plastic bracket attached to the 'A' pillar.
The control module monitors the height of each corner of the vehicle via four height sensors, which are mounted in-board of each road wheel.
The control module has these modes of operation:
^ Calibration
^ Normal
^ Periodic Wake-Up.
When a new air suspension control module is fitted, the air suspension system will not function until the air suspension software is loaded and the system calibrated with T4.
Calibration
A calibration routine is performed using T4 to access the position of each corner of the vehicle and record the settings in the control module memory. Once set, the calibration is not required to be performed unless the air suspension control module is removed or replaced, a height sensor or bracket is removed, replaced or disturbed or a suspension arm to which the sensor is connected is removed or replaced. If the removed height sensor is subsequently refitted, the calibration procedure will have to be performed to ensure the integrity of the system.
If the air supply unit, the reservoir, a valve block, a damper module or the air harness is removed or replaced, the system will not require recalibration.
Periodic Wake-Up Mode
When the vehicle is parked, the air suspension control module 'wakes up' two hours after the ignition was last switched off and once every six hours thereafter. The vehicle height is checked and if the vehicle is not level within a pre-set tolerance, small downwards height adjustments may be made automatically.
Inputs and Output
Air Suspension Control Module Harness Connectors
Air Suspension Control Module Harness Connectors (Part 1):
Air Suspension Control Module Harness Connectors (Part 2):
Connector C2030:
Connector C2320:
Connector C2321:
Connector C0867:
